Moldboard plows



March 31, 1964 w. w. SEWELL MOLDBOARD FLOWS Filed Sept. 25, 1961 Wall.TER W. til-W54 1.

IN V EN TOR.

United States Patent 3,126,969 MOLDBOARD PLGWEi Walter W. Seweil,Washington, Mich, assignor to Ford Motor Company, Dearhorn, Mich, acorporation of Deiaware Filed Sept. 25, 1961, Ser. No. 14%),396 3Claims. (Cl. 1727i9) This invention relates to moldboard plows, and moreparticularly to such plows having an improved construction facilitatingpassage of the soil across the moldboard surface of the plow and turningof a furrow with minimum draft on the plow.

The invention is incorporated in a moldboard plow of more or lessconventional design and contour. According to the present invention, athin steel sheet, which previously has been given a thin, tightlyadherent coating of polytetrafluoroethylene (Teflon) and then formed tomoldboard contour, is applied to the moldboard to provide a smoothsurface of Teflon having a very low coefficient of friction in order topromote scouring.

One feature of the present construction is that the layer of Teflon isthin and tightly adherent to its metal backing. While the Tefion layermay tend to wear rapidly in areas of higher soil pressure of themoldboard, it will wear slowly in areas of low soil pressure, which arethe primary areas in which soil scouring is a problem. Accordingly, aplow according to the present invention will continue to scoursatisfactorily in so-called problem soils" of high moisture content,even though an appreciable portion of the Teflon surface layer has beenworn away, exposing the surface of the sheet to which the Teflon isbonded.

The invention is equally applicable to the soil-contacting surface ofplow jointers, which are mounted immediately above moldboards tofacilitate turning the furrow and improve trash covering.

Among the objects of the present invention are to provide an improvedmoldboard plow construction which is economical to manufacture, whichwill function well in poor scouring soils, which has a relatively longlife, and in which the worn parts may readily be replaced when wornbeyond use; and generally to improve such plows.

Other objects, and objects relating to details of construction, will beapparent from the detailed description to follow.

My invention is clearly defined in the appended claims. In the claims,as well as in the description, parts may at times be identified byspecific names for clarity and con venience, but such nomenclature is tobe understood as having the broadest meaning consistent with the contextand with the concept of my invention as distinguished from the pertinentprior art. The best form in which I have contemplated applying myinvention is illustrated in the accompanying drawings forming part ofthis specification, in which:

FIGURE 1 is an elevation of the moldboard surface of a plow, including ajointer, embodying the present invention.

FiGURE 2 is a plan view of the Teflon coated sheets for covering themoldboard and jointer surfaces of the plow of FIGURE 1.

FIGURE 3 is an enlarged fragmentary section, taken on the line 33 ofFIGURE 1.

FIGURE 4 is an enlarged fragmentary section of the moldboard andcovering sheet, taken on the line 4-4 of FIGURE 1.

FIGURE 5 is an enlarged section of one of the Tefloncovered sheets.

The plow of FIGURE 1 is more or less conventional in shape, having acompound curved moldboard surface, and includes a rigid steel moldboard10, a share 11 and a shin 12, the share and shin lying in a continuationof the curved surface of the moldboard. The moldboard 1%, share 11 andshin 12 are bolted to a frog or frame 14, to which the plow beam (notshown), attaches. The construction of the plow of the present inventionis in most respects conventional, the frog or frame being generallysimilar to that shown in Altgelt United States Patent 2,622,502.

The moldboard share and shin are mounted on a por tion of the frame 14by a scrim of bolts 15. If desired, a plow jointer 16 may be locatedabove the shin 12 and moldboard 10, the forward portion of the jointerlying generally in an upward extension of the surface of the shin andmoldboard, and the rear portion of the jointer curving outwardly beyondthe moldboard surface to aid in turning the furrow cut by the plow. Thejointer, likewise, is supported from the plow frame by bolts 15.

According to the present invention, the plow moldboard 10 is covered bya relatively thin, mild steel sheet 17 conforming generally with theoutline of the moldboard and having a thin, tightly adherent layer oftetrafluoroethylene, commonly known by the trademark Teflon. It has beenfound desirable to utilize steel sheet of a thickness between 15 and 24gauge, preferably about 20 gauge, having a tightly adherent sheet ofTeflon cemented thereto, having a thickness between .010" and .045",preferably about .030".

The Teflon covered sheet 17 preferably is blanked to the form shown inFIGURE 2 and then coated in a well known manner with Teflon before beingformed to the warped contour of the moldboard. It has been found that athin Teflon coating cemented on a thin steel sheet can withstand theforming operation without destroying the bond between the sheets and theTeflon or otherwise adversely affecting the Teflon.

The Teflon covered sheet 17 may be formed to the general contour of themoldboard 10 in the same forming dies which are used to form themoldboard itself. After forming, the sheet 17 is secured to themoldboard 10 by two spaced fasteners or bolts 20 which may also serve tosecure the moldboard to the plow frame 14. Preferably, the bolts 20 arespaced a substantial distance a part, one bolt being toward the forwardend of the sheet and the other bolt towards the rear.

In addition, a series of bendable tabs 21 are formed along the lower andrear edge of the sheet 17 and are adapted to be bent over the lowertrailing edge and rear edge of the moldboard (FIG. 2), to prevententrance and packing of dirt between the sheet and the moldboard, whichwould tend to force the sheet away from the surface of the moldboard.

Sheet metal 2 shaped strips 22 and 24 overlie the edges of the sheet 17adjacent the shin 12 and share 11 to prevent entrance of dirt under theforward portion of sheet 17. Inasmuch as the direction of soil flowacross the moldboard is upwardly and to the left, as viewed in FIG. 1,the strips 22 and 24 and the tabs 21 along the lower trailing edge ofthe moldboard effectively prevent the entrance of dirt behind the sheet.The tabs 21 at the rear of the sheet 17 serve to prevent entrance ofdirt behind the sheet 17 when the plow is pushed rearwardly, as mayoccur from time to time.

The plow according to present invention has a substantially reduceddraft and improved scouring, so that it may be used in wet, sticky soilsthat tend to adhere to a conventional moldboard plow rather than flowingfree ly from the moldboard. The thin coating 19' of Teflon on the sheet17 overlying the moldboard tends to wear away rat-her rapidly in theareas of higher soil pressure adjacent the shin 12 and share 11, so thatafter relatively short usage the Teflon will be worn away entirely inthese areas. Difliculty in scouring, however, occurs in the areas oflesser soil pressure on the moldboard, and in these areas the Teflonwears much more slowly. By utilizing a thin sheet of Teflon which istightly adherent to the steel sheet, there is no tendency of the Teflonto be peeled (from the sheet, and the Teflon is Worn away gradually byabrasion of the soil, commencing in the areas of highest pressure. As -aresult, the plow according to the present invention will continue toscour satisfactorily in problem soils and turn a clean furrow, evenafter the Teflon has been worn completely away from one-third or more ofthe area of the moldboard, the draft of the plow being only slightlyincreased.

After the Teflon 19 has been completely worn away from more thanone-half of the area of sheet 17, the sheet 17 may easily be replaced byremoving the bolts 20 and bending the tabs 21 out of engagement aboutthe edge of the moldboard. A replacement Teflon coated sheet 17 may thenbe inserted under the strips 22 and 24 and bolted into place in asimilar manner, the tabs 21 being bent around the lower trailing andrear edge of the moldboard.

If desired, a similar Teflon coated sheet 25 may be applied to the soilcontacting surface of the jointer 16. The sheet 25 preferably is of mildsteel, corresponds in thickness to the sheet 17 and has a similarcoating of Teflon similarly applied. The sheet 25, which correspondsgenerally to the outline of the jointer 16, may be preformed to thecurved contour of the jointer, or may be flat before application andclamped against the face of the jointer while the tabs 26 along themargin of the sheet are bent about the edges of the jointer. It has beenfound unnecessary to use any means of securing the sheet 25 to the soilcontacting surface of the jointer 16 other than by the tabs 26.

Application of a thin Teflon coated steel sheet to the jointer improvesthe soil turning and trash covering functions of the jointersubstantially in all types of soils. Inasmuch as the soil pressureagainst the jointer is much less than against the moldboard, the Tefloncovered jointer may be used to advantage with plows having aconventional steel moldboard without a Teflon covering and in abrasivesoils which would wear away a coating of Teflon from the moldboardsurface relatively rapidly.

I claim:

1. A moldboard plow having a moldboard surface formed of a moldboard, ashin and a share, the shin and share being mounted generally flush withthe moldboard, a thin metal sheet conforming in general to the outlineof and overlying the moldboard, the metal sheet having a thin, tightlyadherent coating of polytetrafluoroethylene on its exposed face, andmetal strips lying between the confronting edges of the moldboard, shinand share and having narrow flanges overlying the adjacent edges of thepolytetrafluoroethylene-coated sheet.

2. A plow having a moldboard, and a thin metal sheet conforming ingeneral to the outline of and overlying the moldboard, the metal sheethaving a thin, tightly adherent coating of polytetrafluoroethylene onits exposed face, the thickness of the metal sheet being betweenapproximately 15 and 24 gauge and the thickness of thepolytet-rafluoroethylene coating being between approximately .010 and.045 of an inch.

3. A plow having a moldboard, a thin metal sheet conforming in generalto the outline of and overlying one face of the moldboard and having oneface thereof exposed, the metal sheet having a thin, tightly adherentcoating of polytetrafluoroethylene on its exposed face, at least onebolt extending through the metal sheet and moldboard, and tab means onat least one of the marginal edges of said metal sheet overlying thecorresponding edge of said moldboard to aid in holding said metal sheeton said moldboard.

References Cited in the file of this patent UNITED STATES PATENTS 72,305Leach Dec. 17, 1867 1,903,723 Palmer Apr. 11, 1933 2,672,805 LongenbachMar. 23, 1954 2,727,845 Bishop Dec. 20, 1955 2,913,060 Owen et a1 Nov.17, 1959

1. A MOLDBOARD PLOW HAVING A MOLDBOARD SURFACE FORMED OF A MOLDBOARD, ASHIN AND A SHARE, THE SHIN AND SHARE BEING MOUNTED GENERALLY FLUSH WITHTHE MOLDBOARD, A THIN METAL SHEET CONFORMING IN GENERAL TO THE OUTLINEOF AND OVERLYING THE MOLDBOARD, THE METAL SHEET HAVING A THIN, TIGHTLYADHERENT COATING OF POLYTETRAFLUOROETHYLENE ON ITS EXPOSED FACE, ANDMETAL STREIPS LYING BETWEEN THE CONFRONTING EDGES OF THE MOLDBOARD, SHINAND SHARE AND HAVING NARROW FLANGES OVERLYING THE ADJACENT EDGES OF THEPOLYTETRAFLUOROETHYLENE-COATED SHEET.